[PATCH 5.4 050/104] usb: chipidea: core: fix possible concurrent when switch role

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Xu Yang <xu.yang_2@nxp.com>

commit 451b15ed138ec15bffbebb58a00ebdd884c3e659 upstream.

The user may call role_store() when driver is handling
ci_handle_id_switch() which is triggerred by otg event or power lost
event. Unfortunately, the controller may go into chaos in this case.
Fix this by protecting it with mutex lock.

Fixes: a932a8041ff9 ("usb: chipidea: core: add sysfs group")
cc: <stable@vger.kernel.org>
Acked-by: Peter Chen <peter.chen@kernel.org>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20230317061516.2451728-2-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/chipidea/ci.h   |    2 ++
 drivers/usb/chipidea/core.c |    8 +++++++-
 drivers/usb/chipidea/otg.c  |    5 ++++-
 3 files changed, 13 insertions(+), 2 deletions(-)

--- a/drivers/usb/chipidea/ci.h
+++ b/drivers/usb/chipidea/ci.h
@@ -203,6 +203,7 @@ struct hw_bank {
  * @in_lpm: if the core in low power mode
  * @wakeup_int: if wakeup interrupt occur
  * @rev: The revision number for controller
+ * @mutex: protect code from concorrent running when doing role switch
  */
 struct ci_hdrc {
 	struct device			*dev;
@@ -256,6 +257,7 @@ struct ci_hdrc {
 	bool				in_lpm;
 	bool				wakeup_int;
 	enum ci_revision		rev;
+	struct mutex                    mutex;
 };
 
 static inline struct ci_role_driver *ci_role(struct ci_hdrc *ci)
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -963,8 +963,12 @@ static ssize_t role_store(struct device
 	if (role == CI_ROLE_END)
 		return -EINVAL;
 
-	if (role == ci->role)
+	mutex_lock(&ci->mutex);
+
+	if (role == ci->role) {
+		mutex_unlock(&ci->mutex);
 		return n;
+	}
 
 	pm_runtime_get_sync(dev);
 	disable_irq(ci->irq);
@@ -974,6 +978,7 @@ static ssize_t role_store(struct device
 		ci_handle_vbus_change(ci);
 	enable_irq(ci->irq);
 	pm_runtime_put_sync(dev);
+	mutex_unlock(&ci->mutex);
 
 	return (ret == 0) ? n : ret;
 }
@@ -1009,6 +1014,7 @@ static int ci_hdrc_probe(struct platform
 		return -ENOMEM;
 
 	spin_lock_init(&ci->lock);
+	mutex_init(&ci->mutex);
 	ci->dev = dev;
 	ci->platdata = dev_get_platdata(dev);
 	ci->imx28_write_fix = !!(ci->platdata->flags &
--- a/drivers/usb/chipidea/otg.c
+++ b/drivers/usb/chipidea/otg.c
@@ -164,8 +164,10 @@ static int hw_wait_vbus_lower_bsv(struct
 
 static void ci_handle_id_switch(struct ci_hdrc *ci)
 {
-	enum ci_role role = ci_otg_role(ci);
+	enum ci_role role;
 
+	mutex_lock(&ci->mutex);
+	role = ci_otg_role(ci);
 	if (role != ci->role) {
 		dev_dbg(ci->dev, "switching from %s to %s\n",
 			ci_role(ci)->name, ci->roles[role]->name);
@@ -188,6 +190,7 @@ static void ci_handle_id_switch(struct c
 		if (role == CI_ROLE_GADGET)
 			ci_handle_vbus_change(ci);
 	}
+	mutex_unlock(&ci->mutex);
 }
 /**
  * ci_otg_work - perform otg (vbus/id) event handle